Carlos Alberto Solano Ortiz

Carlos Alberto Solano Ortiz

Carlos Alberto Solano Ortiz was born in Colombia and arrived in the United States before his 15th birthday. He is interested in nanomaterials for use in alternative energy. Carlos actively pursued research at the university level by contacting faculty and asking if he could work for them. His tenacity paid off, and he is now conducting research under the mentorship of Dr. Lee Chow, the associate chair of the Physics Department. His task was to keep nanoparticles from agglomerating in a substrate where they would aid in the growth of carbon nanotubes. He then started working in Research Parkway with Dr. Swadeshmukul Santra from the Chemistry Department. Carlos participated in the SURF program in the summer of 2009 at Yale University, working with Dr. Charles Ahn’s group and learning about the atomic force microscope (AFM). He is the outreach coordinator of the Society of Physics Students at UCF and has been active with local middle schools in getting students interested in physics and nanotechnology. His group was awarded the Marsh White Award from the American Physical Society for this endeavor. The following are abstracts of research Carlos completed as an undergraduate at UCF:

Conducted at Yale University as part of the SURF program in the summer of 2009

Abstract: Complex oxides are the subject of intense research due to the wide variety of behaviors they display, including drastic changes in its metallic properties when exposed to weak magnetic fields, known as colossal magnetoresistance (CMR). The physics behind this phenomenon is still under debate, but the roughness of the material is known to affect it. In this project, the morphology of the CMR oxide lanthanum strontium manganite (LSMO, La0.65Sr0.35MnO3) has been studied using atomic force microscopy (AFM). The principles of the AFM itself have been learned and applied. A basic understanding of thin film growth was required in order to correlate surface morphology to epitaxial growth modes. The basics of the synthesis equipment, off-axis radio frequency (RF) magnetron sputtering, were learned. Thin film growth was optimized by observing the quality of the films obtained under different growth conditions. 27 samples were analyzed and over 250 images taken, which provided interesting results. Two samples showed a difference in roughness at different locations. Substrate-induced strain was studied by growing the LSMO on different substrates; namely, strontium titanate (STO, SrTiO3) and lanthanum aluminate (LAO, LaAlO3). Scanning at different degrees did not demonstrate significant differences in measurements. A graph of roughness vs. film thickness shows a similar trend with both substrates, with LAO having a larger average roughness. These results provide a starting platform for future research on LSMO, which may include growing at different thicknesses on STO and LAO or growing on different substrates with different lattice constants.

Conducted at the University of Central Florida as part of the Ronald E. McNair Scholars Program.

Abstract: Cerium Oxide is a rare earth oxide that has attracted a great deal of interest owing to its unique properties, including: high mechanical strength, oxygen ion conductivity and oxygen storage capacity, autocatalytic properties and free radical scavenging properties. Several methods have been employed to synthesize ceria nanoparticles, particularly: hydroxide co-precipitation of a precursor solution composed of cerium ammonium nitrate and zirconyl chloride followed by sonication, flame combustion method, microemulsion process, sonochemical and microwave-assisted heating method, etc. To date, ceria NPs synthesized by above-mentioned methods are often highly aggregated and large scale synthesis of monodispersed NPs is quite challenging. Only a few organic solvent assisted synthesis or post-synthesis surface engineering could produce well dispersed, water-soluble ceria nanoparticles.

The objective of this project is to provide a low cost, high yield, facile procedure to synthesize monodispersed and water soluble ceria nanoparticles, whose demand is rapidly growing in the biomedical field. The ceria NPs were synthesized by solvothermal treatment with fixed amounts of Ce(NO3)•6H2O (Cerium Nitrite) and EuCl3 (Europium Chloride) with water as the solvent. All samples were placed in the oven for five hours. Different temperatures and sodium hydroxide (NaOH (g)) concentrations were studied. Dopant (Eu) based nanostructures were successfully synthesized. Different conditions yielded different structures at different dimensions (10nm and 400nm). Upon doping, mixed valence state (Ce3+ and Ce4+) was observed by changes in optical and catalytic properties (through UV-Vis spectroscopy). These results require further testing at the interface conditions between structures.